Aircraft seat

ABSTRACT

An aircraft seat includes a seat cushion and a seat back. The seat cushion has a rear portion along the seat back and a front portion of complementary shape to the rear portion to form a complete seat cushion. The rear portion moves between a raised position and a lowered position. A coupling arrangement connects the front portion to the rear portion so that when the front portion is in the raised position along the seat back the front portion is in the lowered position, in which at least part of it is retracted under the rear portion. When the rear portion is in its lowest position along the seat back the front portion is in a raised, advanced position at the same height as the rear portion to form therewith the seat cushion of the seat for receiving a seated passenger.

BACKGROUND OF THE INVENTION

[0001] 1. Field of the Invention

[0002] The present invention relates to a new type of aircraft seat.

[0003] 2. Description of the Prior Art

[0004] Available space in aircraft is an ongoing problem. To maximizethe profit on an aircraft flight, the greatest possible number ofpassengers must be carried. A seat must be provided for each passenger.The problem then arises of providing the greatest number of seats in agiven space, that of the aircraft cabin. It is also necessary for thepassengers to be comfortable.

[0005] International safety standards impose a minimum space for eachpassenger. For example, in the event of an accident, if the head of apassenger is thrown forward, it must not strike the back of the seat infront, the passenger being secured by a seat belt, of course. If thisstandard is only just complied with, the seat cushion occupies twothirds of the distance between two successive seat backs and theremaining third is available for the legs of the seated passenger andfor moving around, in particular to access the seat.

[0006] In economy class in particular, the small space for moving aroundbetween two rows of seats generally prevents natural movement, requiringa passenger to move sideways and to lean over, to adapt to theinclination of the seat backs.

[0007] An object of the present invention is provide a new aircraft seatfacilitating movement of passengers between two successive rows ofseats.

SUMMARY OF THE INVENTION

[0008] To this end, the present invention proposes an aircraft seatincluding a seat cushion and a seat back, wherein the seat cushion has arear portion along the seat back and a front portion of complementaryshape to the rear portion to form a complete seat cushion, the rearportion is mobile between a raised position and a lowered position, andcoupling means connect the front portion to the rear portion so thatwhen the front portion is in the raised position along the seat back thefront portion is in the lowered position, in which at least part of itis retracted under the rear portion, and when the rear portion is in itslowest position along the seat back the front portion is in a raised,advanced position at the same height as the rear portion to formtherewith the seat cushion of the seat for receiving a seated passenger.

[0009] This kind of seat provides more room to move around when thefront portion of the seat cushion is retracted under the rear portion,whilst offering a comfortable seat with good support for the thighs whenthe front portion is aligned with the rear portion.

[0010] In one advantageous embodiment, spring means spring-load the rearportion of the seat into its raised position, enabling the seat tofunction “automatically”, i.e. without the passenger having to concernhimself with the position of the seat cushion.

[0011] In one embodiment of a seat according to the invention the rearportion of the seat cushion is adapted to slide along the seat back.

[0012] The front portion moves from its lowered (retracted) position toits raised (advanced) position with a movement that is a combination ofa movement in translation toward the front and a rotation, for example.It is nevertheless also possible to make provision for only a movementin translation or only a rotation.

[0013] In one embodiment, the front portion of the seat is connected tothe rear portion by at least two links forming a deformable trapeziumand one of these links is connected by a third link to a fixed point.

[0014] The front and rear portions of the seat cushion preferably eachaccount for substantially half the surface area of the seat cushion whenthey are at the same height.

[0015] In an advantageous embodiment, the seat includes latching meansfor latching the rear portion of the seat cushion in its raisedposition. The seat can then be used for a child, in the manner of ahighchair.

[0016] For improved resistance to heavy loads, the seat includes a fixedreinforcement disposed substantially vertically underneath it, forexample, and the rear portion of the seat cushion has a housing toreceive an upper portion of the reinforcement when the rear portion isin its lowered position. The reinforcement can comprise two verticaltubes linked by a transverse bar.

[0017] Details and advantages of the present invention will emerge moreclearly from the following description given with reference to theaccompanying diagrammatic drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

[0018]FIG. 1 is a side view of a seat according to the invention in a“rest” configuration.

[0019]FIG. 2 is a side view of the FIG. 1 seat in an “in use”configuration.

[0020]FIGS. 3A to 3C are diagrams showing the movement from theconfiguration shown in FIG. 1 to the configuration shown in FIG. 2.

[0021]FIG. 4 is a partial front view of the seat shown in FIG. 1.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

[0022] The aircraft seat shown in the figures includes a seat cushion intwo parts, a seat back 2 with a headrest 4 at the top, and legs 6.

[0023] The seat has two legs 6 supporting the seat back 2 and the seatcushion. The legs are aligned with the seat back 2. For example, theseat can include two facing and substantially vertical beams fixed tothe floor at the bottom. The bottom portion of the beams, close to thefloor, then serves as a base for the seat, and the upper portion is usedto fix the seat back 2.

[0024] The seat shown in the drawings is fixed to the horizontal floor 8of an aircraft cabin. An arrow 10 indicates the direction of movement ofthe aircraft in flight and defines a longitudinal axis. Thus in thefigures the forward direction is to the left and the rearward directionis to the right.

[0025] The seat cushion has a front portion 12 and a rear portion 14.The two portions 12 and 14 have complementary shapes to form a completeseat cushion as shown in FIG. 2. The junction surface between the frontand rear portions 12 and 14 of the seat cushion is substantially plane.This junction plane 16 is inclined at approximately 45°. It extendsdownward in the direction from the rear toward the front and forms aseat cushion junction line 18 substantially parallel to the seat back 2.The distance between the junction line 18 and the seat back 2 issubstantially equal to the distance between the junction line 18 and thefront edge 20 of the seat cushion, which is the most forward portion ofthe seat cushion.

[0026] As can be seen in the figures, the front and rear portions 12 and14 are mobile relative to each other and also relative to the fixed seatback 2.

[0027] The rear portion 14 of the seat cushion can move in substantiallyvertical translation along the bottom portion of the seat back 2. Oneach side of the seat, at the level of the top portion of the legs 6,there is a pneumatic cylinder 22. Each cylinder 22 is fixed at thebottom end to the corresponding leg 6 and at the top end to anattachment lug 24 fastened to the rear portion 14 of the seat cushion.The rear portion 14 can be guided on the seat back 2 by co-operation ofmatching shapes of the rear portion 14 and the seat back 2, for example.Alternatively, guide fingers can be provided on the rear portion 14,each sliding in a corresponding groove in the beams forming the legs 6and supporting the seat back 2, for example.

[0028] The front portion 12 of the seat cushion is connected to the rearportion 14 by links. It is possible to provide a single set of linkssituated substantially in the median longitudinal plane of the seat ortwo sets of links symmetrically placed relative to that medianlongitudinal plane. In the latter case, the links are then on the sidesof the seat, for example, but in this case they are preferablystreamlined to prevent trapping fingers or objects. Other solutions canalso be envisaged. However, configurations in which the seat issubstantially symmetrical relative to its median longitudinal plane arepreferred. The remainder of the description applies to only one set oflinks.

[0029] Thus the front portion 12 is connected to the rear portion 14 bya top link 26 and a bottom link 28. The links 26 and 28 are bothdisposed in a longitudinal vertical plane and define a trapezium. Afirst end of each link pivots on the rear portion 14 of the seat cushionand the other end of each link pivots on the front portion 12 of theseat cushion. The respective attachment points of the top link 24 to therear portion 14 and the front portion 12 are higher than the points ofattachment of the bottom link 28 to the rear portion 14 and the frontportion 12, respectively.

[0030] Accordingly, the relative movement between the rear portion 14and the front portion 12 is a combination of a movement in a translationand a rotation. As can be seen in FIGS. 1 and 2, in the “in use”configuration (FIG. 2) the front portion 12 is almost horizontal and infront of the rear portion 14 and in the “rest” configuration (FIG. 1)the front portion 12 is retracted relative to the rear portion 14 and atleast part of it is under the latter.

[0031] The lengths of the links and the positions of the attachmentpoints are chosen so that in a first position the front portion 12cooperates with the rear portion 14 to form a seat cushion and in therest position at least part of the front portion 12 is retracted underthe rear portion 14.

[0032] Note that, as shown in the figures, the bottom link 28 isconnected by a third link 30 to a base 32. This connection to the floorcouples the movement of the rear portion 14 relative to the seat back 2with the relative movement of the front and rear portions 12 and 14 ofthe seat cushion.

[0033] The base 32 also carries a reinforcement formed by two verticaltubes 34 linked by a transverse bar 36. FIG. 4 is a front view of thereinforcement. Note that, as shown in FIG. 4 and FIG. 1, the rearportion 14 of the seat cushion has two housings 38 facing the free topends of the tubes 34. The housings 38 are formed in the structure of therear portion 14 of the seat cushion. The tubes 34 are relatively farback, so that they do not impede the movement of the front portion 12 ofthe seat cushion. Their height is such that when the rear portion 14 isin its lowest position (see FIGS. 2 and 3C), the free ends of the tubes34 are in the housings 38.

[0034] How the seat works is described hereinafter with reference toFIGS. 3A to 3C.

[0035] In FIG. 3A, the seat is in the rest configuration and a passengeris about to sit on it. The rear portion 14 of the seat cushion is in itshighest position. This position can be limited in various ways, forexample stop(s) on the seat back and/or the seat cushion, end of travelstops on the cylinders 22, etc. The front portion 12 of the seat cushionis retracted under the rear portion 14. This position is defined by thelengths of the links 26, 28 and 30 and by the position of the attachmentpoints of the links. The pneumatic cylinders 22 apply a spring returnforce to the rear portion 14 of the seat cushion in this highestposition of the rear portion 14. Here the front portion 12 of the seatcushion can come into contact with the tubes 34 of the reinforcementplaced under the seat. If necessary, the reinforcement can limit themovement of the portions 12 and 14 of the seat cushion and thereby formthe stop(s) defining the highest position of the rear portion 14 and theretracted position of the front portion 12.

[0036] When the passenger begins to sit down (see FIG. 3B), he firstcomes into contact with the rear portion 14. The passenger's weightapplies a force in opposition to the force exerted by the pneumaticcylinders 22, and the rear portion 14 of the seat cushion thereforedescends. Because of the third link 30, the bottom link 28 is pushedupward, entraining the front portion 12 of the seat cushion. The frontportion 12 then moves forward and tilts until it is virtuallyhorizontal. The pneumatic cylinders 22 damp the downward movement of thepassenger.

[0037] When the passenger is entirely seated (see FIG. 3C), his weightis supported primarily by the rear portion 14 of the seat cushion, whichis in its lowest position, which can be defined in various ways, forexample by stop(s) limiting the downward movement in translation of therear portion 14 of the seat cushion. These stop(s) can be integratedinto the pneumatic cylinders 22 and/or the seat back 2 and/or the legs 6and/or the rear portion 14. Alternatively, the same effect can beobtained when the front portion 12 is positioned relative to the rearportion 14 to form a complete seat cushion, or by the reinforcementunder the seat, when the tubes 34 come into contact with the bottom ofthe corresponding housings 38.

[0038] In this position (see FIG. 3C), the reinforcement under the seatassists it to absorb high forces. The transverse bar 36, by linking thetwo tubes 34, also increases the resistance of the seat to side loads.Thus the seat can absorb longitudinal accelerations of 16 g andtransverse accelerations of 7 g (1 g=9.81 ms⁻²).

[0039] In a different embodiment, latching means can be provided tolatch the seat in its rest position (see FIGS. 1 and 3A), in which therear portion 14 of the seat cushion is in the raised position and thefront portion 12 is retracted under the rear portion 14. There can bemultiple latches. For example, latches can be integrated into thepneumatic cylinders 22 to prevent the rear portion 14 descending. Therecan also be a latch to prevent the rear portion 14 of the seat cushionfrom descending. The link 30 can also be latched. In this latter case,the latching means are advantageously provided with foot-operatedcontrol means.

[0040] Latching the seat in its rest position enables the seat to beused for a child. The child is then seated only on the rear portion 14and is therefore raised up. Moreover, in this position the length of theseat cushion is better suited to the size of a child. Thus youngpassengers can travel much more comfortably than on conventional seats.

[0041] The seat according to the invention is as comfortable for apassenger as a conventional aircraft seat. When seated, the distancebetween the front edge 20 of the seat cushion and the seat back 2 can beidentical to that of a conventional seat. The passenger therefore hasthe benefit of equivalent thigh support. When he is not seated, thepassenger has more room to move around, for example to take off agarment, or to place a bag in a luggage locker, etc.

[0042] If the space between two successive seats is too small, deep veinthrombosis problems can arise on long-haul flights. A seated passengerlacks room to move around and his blood does not circulate properly. Athrombosis can then result. A seat according to the invention can helpto solve these problems. The passenger has more room when he stands up.He can then move around, for example squat, without disturbing hisneighbors. This exercise encourages blood circulation and preventsthrombosis.

[0043] The movement of the seat cushion does not disturb the passengerwhen he sits down or stands up. He has no need to perform any particulargesture for the seat cushion to be positioned correctly, unlikeconventional folding seats, in which the whole seat cushion pivots fromits substantially horizontal position of use to a substantially verticalrest position along the seat back. With conventional seats, movement ofthe seat cushion toward its horizontal position must be started with thehand before the passenger can sit down.

[0044] The seat according to the invention has the advantage ofassisting the passenger to sit down. The passenger comes into contactwith the seat sooner and the last phase of his descent is damped,especially if the seat incorporates spring means.

[0045] Like aircraft seats in general, a seat according to the inventioncan accommodate a life vest. The mechanism of the seat is compact andleaves a large free space under the seat, both in the rest configurationand in the in use configuration. This free space can also be used forthe comfort of passengers and can provide space for the feet of thepassenger seated on the seat or the feet of a passenger seated behindthe seat.

[0046] Because of the increased room to move around between rows ofseats, when the seats are not occupied embarkation and disembarkationtimes can be reduced. Passengers can move around more easily andtherefore faster.

[0047] What is more, the flight crew and passengers can be served moreeasily, especially when the aircraft has at least two aisles. If one ofthe aisles is temporarily blocked and there is at least one row of emptyseats between the aisles, it is easy to move from one aisle to theother, even with a trolley (or cart).

[0048] The present invention can be applied to seats of any shape. Themechanism described above can be adapted to suit virtually all seats.For simplicity, no armrests are shown in the drawings. Armrests cannevertheless be provided, either fastened to the seat cushion,preferably to the rear portion thereof, or to the seat back (or thelegs).

[0049] The present invention is not limited to the preferred embodimentdescribed above by way of non-limiting example. To the contrary, itencompasses all embodiments within the scope of the following claims.

[0050] For example, other kinematic systems could be envisaged betweenthe rear portion and the front portion of the seat cushion. The top andbottom links could form a parallelogram, for example. In this case, therelative movement between the two portions of the seat cushion would bea movement in translation only. Alternatively, a single link could beprovided between the two portions of the seat cushion. Other mechanismswith a return point, like a swing, could be envisaged.

[0051] The movement of the front portion of the seat cushion beinglinked to the movement of the rear portion, the spring return forces canequally well be exerted on the front portion of the seat cushion or on amechanism connecting the two portions of the seat cushion to spring-loadthe rear portion toward its raised position. The spring return means areoptional. Obviously means for returning the seat cushion to the restposition are advantageous. Instead of providing spring means (pneumaticcylinders, springs, etc.), other means can also be envisaged (offsetcentre of gravity, counterweight, etc.).

1-9. (Canceled)
 10. An aircraft seat for an aircraft cabin having afloor, said aircraft seat comprising: a frame member; a seat backmounted to said frame member; a seat cushion having a rear portionmovably mounted to one of said seat back and said frame member and afront portion mounted adjacent said rear portion, said front portionhaving a front end segment and a rear end segment opposite said frontend segment; means for biasing said rear portion of said seat cushionbetween a raised position and a lowered position said means for biasingmounted between said rear portion of said seat cushion and said framemember; means for moving said front portion of said seat cushion from afirst lower retracted position to a second raised extended positionwhereby in said first lower retracted position said rear end segment ofsaid front portion of said seat cushion is moved substantiallyunderneath said rear portion of said seat cushion and in said secondextended position, said front portion is moved to fully extend such thatsaid front end segment of said front portion of said seat cushion ismoved to extend from said rear portion at substantially the same heightas said rear portion of said seat cushion to provide a seat for apassenger.
 11. The aircraft seat as claimed in claim 10 wherein saidmeans for biasing said rear portion of said seat cushion biases saidrear portion of said seat cushion in an upward direction.
 12. Theaircraft seat as claimed in claim 10 wherein said means for biasing is aspring.
 13. The aircraft seat as claimed in claim 10 wherein said meansfor biasing is a pneumatic cylinder.
 14. The aircraft seat as claimed inclaim 11 further comprising means for latching said rear portion of saidseat cushion at said upward direction.
 15. The aircraft seat as claimedin claim 10 wherein said means for moving said front portion of saidseat cushion further comprises a four-bar linkage connecting said rearportion of said seat cushion with said front portion of said cushion;and a fixed link member having one end fixed to said aircraft said cabinand an opposite end attached to at least one link of said four-barlinkage.
 16. The aircraft seat as claimed in claim 10 wherein themovement of said front portion of said cushion from said first loweredposition to a second raised position is a combination of a movement intranslation in a forward direction and a rotation.
 17. The aircraft seatas claimed in claim 10 further comprising means for supporting said rearportion of said seat cushion when said rear portion is in said loweredposition.